The long-term goal of this study, initiated in June, 1991, is to express and characterize the protein encoded by the recently isolated cDNA for the putative Type I interferon receptor. Currently, very little is known about the biochemical and functional nature of the receptor protein. The plasmid containing the cDNA has been obtained from American Type Culture Collection. Initial efforts will be directed toward engineering the cDNA for optimal expression in different systems, both bacterial and mammalian. In addition, efforts to generate a soluble form of the receptor protein are underway. The protein products will be purified and used to generate both polyclonal and monoclonal antibodies to the protein. In addition, experiments will be performed to assess the capacity of this protein to bind various species of human interferon ` readily available in our laboratory. These studies should lead to an enhanced understanding of ligand-receptor interactions in the interferon system.